DESCRIPTION: The applicant proposes to carry out systematic preliminary crystallization studies on more than twenty proteins per year. The proteins are to be provided by other projects of the program. Procedures to be developed or improved to maximize the throughput include: pre- screening of protein samples, rapid crystallization screens, crystal growth optimization techniques, initial X-ray evaluation of protein crystals for suitability for a structure determination, assessment of cryoprotectants and flash-frozen crystal quality, atoms for MAD or MIR/SIR phasing, and methods for crystal transport for remote data collection. The goal of twenty proteins per year assumes a yield of 50%, i.e., that this would enable the generation of crystal structure of at least ten unique proteins per year.